ENVIRONMENTAL POLLUTION.ppt _Compatibility Mode_

(1)

8/21/2007

ENVIRONMENTAL POLLUTION

from

PROCESS INDUSTRIES

Lecture

Lecture -- 11

11 In this lecture

• Pollution and Pollutants

• Types of Pollution

• Effects of Pollution

• Managing Pollution

Pollution

-Introduction by man, waste matter or surplus

energy into the environment, which directly or

indirectly

causes

damage

to

man

and

his

environment

(2)

Pollutant

-

A

substance

or

effect

which

adversely alters the

environment

by

changing

the growth rate of species, interferes

with

the

food chain, is toxic, or interferes with health,

comfort amenities or property values of people

The Issue

• We use

Resources

extensively

and then are

NOT

responsible for

• The

Consequences

!!!

Aral Sea Aral Sea Man made environmental Man made environmental

disaster disaster

(3)

EFFECTS ON BIOSPHERE

1. Damage

to

human

health

by

specific

chemical substances present in the air, food,

water and radioactive material

2. 2. Damage

Damage to

to natural

natural environment

environment affecting

vegetation, animals, crops, soil and water

3. Damage to visual quality by smoke, fumes,

dust, noise and waste

4. Damage

by

carcinogens,

radioactive

materials and excessive noise

Pollution and effects

Minamata Disease

(Jinzu river, Japan)

Learning from the Past

…

Japan

• Fueling consumerism

…

. Doubling income

……

three basic consumer items

…

..

Bioaccumulation

water zooplankton_{0.04 ppm} small fish_{0.5 ppm} large fish_{2 ppm} _{25 ppm}birds

e.g DDT

(4)

Story of Bold eagle In USA

from

Paracelsus ....

Anything and

Everything is toxic if

the dose is made so !!

Paracelsus

(1493-1541)

Toxicity is Quantity related ..

Drinking water and death ! ..

• Woman dies

after

water-drinking

contest

SACRAMENTO, Calif. –

A woman who competed in a radio station’s contest to see how much how much water she could drink without going water she could drink without going to the bathroom

to the bathroom died of water

intoxication, the coroner’s office said Saturday.

2007 !

Waste takes many forms

(5)

TYPES OF POLLUTION

• Water Pollution

• Air Pollution

• Land Pollution

• Noise Pollution

• Thermal Pollution

• Electro Pollution

• Visual Pollution

Water Pollution

–

with what?

• Water ( about 99%)

• Solids

• Carbohydrates

• Proteins

• Fats

• Nutrients (Nitrogen and Phosphorus)

• Microorganisms.

(On average there are about 10 million per

ml of wastewater. Many are pathogens)

These are referred to as

‘

organic material

’

Water Pollution

Inorganic materials - alkalis, acids, inorganic salts, ammonia, phosphates, etc.

Heavy metals - chromium, mercury, nickel, copper, cadmium etc.

Disinfection byproducts - trihalomethanes Other harmful substances - organochlorides etc.

(6)

Organic Pollutants

Inorganic Pollutants

Heavy metal Pollutants

Pathogenic Pollutants

Industrial Sources Responsible

for Organic Pollution

Distillery

Canning

organic

Depletion of DO

Sugar

matter

(7)

Dissolved Oxygen

Industrial Sources

Responsible for Inorganic

Pollution

Fertilizer

algal blooms

reduced light

Soap and detergent

penetration

ammonia

and

Rubber and latex

re-aeration

phosphates

(eutrophication)

Agricultural farms

Sources

Effluent

Problems

Fertiliser Application

(8)

Industrial Sources Responsible for Heavy

Metal Pollution

Paper and pulp

Mercury

-

Minamata disease

Chromium

toxic to aquatic life

Tanneries

Iron

and self purifying

Nickel

organisms

Textile

Lead

Zinc

Toxic to humans

Coke-oven

Arsenic

Cadmium -

Itai-itai disease

Metal plating

Copper

Bio accumulate

Silver

Sources

Effluent

Problems

Sources Discharging Pathogenic

Organisms

Sewage Cholera, typhoid,

Bacteria dysentery, Farm slurry gastroenteritis

diarrhea, salmonellosis Hospital waste Viruses polio, hepatitis,

Protozoa Diarrhea, dysentery, Medical laboratory (Giardia, amebiasis

Cryptosporidium)

Food processing Helminths Roundworm infestation, pinworm,

beef tapeworm, pork tapeworm

Sources

Organism

Diseases

b) Air Pollution

Air is considered safe when it contains no

harmful dust and gases.

Polluted air affects:

Humans

Animals

Vegetation

Materials

(9)

Effects from Air Pollution

• Global warming

• Ozone depletion

(Ozone hole)

• Acid Rain

• Various

respiratory

illnesses

Air Pollution

has

No

Boundaries

Metal foundry refining in early industrial Germany, 1870s Metal foundry refining in early industrial Germany, 1870s

Pollution of air

Particulate Matter PM10 (<10ìm)

- Dust (e.g. cement dust, bagasse, foundry

dust and wind blown solid dust)

- Mist

- Smoke

- Carbon black

- Aerosols

(10)

The

Problem

of

DUST

SPM

PM 10

PM 2.5

etc.

Radioactive

nucleids

Air Pollution and Health

Some Polluting Process Industries

Sulfuric Acid Plants

Thermal Power Stations

Nitric Acid Plants

Cement Plants

Foundaries

Plastic Industries

TRANSPORTATION

Three modes of transport

• Air ( airplanes etc.)

• Sea (ships, boats etc.)

• Land (automotive & locomotive)

Products of combustion of fuels are CO, CO

2

,

NO

_x

, hydrocarbons, particulate matter and

traces of SO

₂

, formaldehyde and Pb.

(11)

c) Land Pollution

Urbanization and Concentration of Population

Municipal Solid Waste

Industrial Waste and Hazardous Waste

Uncontrolled “Land Treatment”

Burning open dumps and forest fires

Deforestation

Mining and Erosion

This is within our

university

d) Noise Pollution

Exposure to prolong noise affects speech,

hearing, general health and behaviour.

Noise Levels – dB

Intensity

frequency

periods of exposure and

duration

(12)

Human hearing and Frequency

0 16 Hz 20 kHz 5 MHz

Intensity (Loudness)

• Measure of acoustic

energy of the sound

vibrations

• Expressed in terms of

sound pressure

• Decibels (dB) are the

unit of measurement

on the Loudness

scale

Physical Characteristics of Sound

• Measurement and human perception of

Sound involves three basic physical

characteristics:

–

Intensity

–

Frequency

–

Duration

How sound is measured

•Pressure, P, usually Pascals

•Frequency, f, usually Hertz

•Intensity, I, usually W/m2

•Bels, L’, derived from logarithmic ratio

•Decibels, L, derived from bels

P= 1/f

I = W/A

L’ = log (Q/Qo)

L = 10*log (Q/Qo)

E.g. Implications of the decibel scale: doubling sound level

would mean that the sound will increase by 10*log2 = +3dB

(13)

Adding decibels

Comparative Noise Levels (dB)

Walkman (1/2 volume)

94 Telephone Dial tone

80 Talking at Three Feet

65 Quiet Urban Daytime

50 Quiet Urban Nighttime

40 Quiet Rural Nighttime

25 Industrial Noise Sources

• Metal fabrication (pressing, grinding, chipping etc.) • High pressure burners in furnaces

• Turbines • Compressors • Pumps

• Welding machines • Cranes and other vehicles

• Pipe lines carrying high velocity fluids and solids •Vibrating and grinding equipment

Electropollution !

- a growing

(14)

Power Lines and

Leukemia

• “..children living in proximity to

high voltage powerlines are at increased risk of childhood leukaemia, but in finding effects

up to 600 metres away, they invoke electric field corona ion effects as a possible causal mechanism.

Prof. Denis Henshaw, Professor of Human Radiation Effects at the University of Bristol

http://news.bbc.co.uk/1/hi/health/3967073.stm

http://www.electric-fields.bris.ac.uk/

Pollution Management

Pollution can be controlled by

proper choice of preventive

and remedial measures

Techniques are changing

…

Techniques are changing

…

Dispersion Pollution Control Recycling Pollution Prevention Sustainable Development 1960 1980 1990

Complexity of Environmental Issue

Cleaner Production

Wastewater Treatment

Volume reduction Strength reduction

Preventive

Physical

Chemical

Biological

Curative

(15)

Typical Wastewater

Processing

Primary Treatment Secondary Treatment Tertiary Treatment Wastewater Wastewater

Primary sludge Secondary Sludge Tertiary Sludge Air emissions

(16)

Physical Methods

Objective

Remove solid or

liquid pollutants

based on density

difference or other

physical property

(eg. SS or floating

solids)

• Solvent extraction

• Evaporation

• Distillation

• Filtration

• Reverse Osmosis

• Electrodialysis

• Adsorption

Biological waste water treatment



Aerobic treatment



Anaerobic treatment

The organic load is defined by the Biological

Oxygen Demand (BOD).

In aerobic systems the water is aerated with

compressed air (in some cases oxygen).

Anaerobic systems run under oxygen free

conditions

–

biogas is a useful product.

• Metabolism:

Organic Nitrogen NH

₃

NH

₃

+ O

₂

NO

₂-

_{+ Energy}

NO

₂-

_{+ O}

2

NO

3-

+ Energy

Bacterial decomposition and hydrolysis

Nitrification

Activated Sludge System

(17)

Chemical Wastewater Treatment

• Neutralization - NaOH, Ca(OH)

2

, HCl, H

2

SO

4

• Coagulation and

Flocculation

- Alum, FeSO

₄

,

• Oxidation

- Sodium hypochlorite

• Disinfection

- Cl

2

, O

3

, NaOCl

Ozonation

…...

Dye Solutions

subjected to ozonation

Air Pollution Control

• Use tall stacks

• Source reduction by process and raw

material changes (eg. Improved furnace

design and low S fuel)

• Recover valuable material (eg. Hg)

• Bag filters, scrubbers, ESP, cyclone

separators

• Absorption, adsorption, combustion and

catalytic reaction

(18)

Blue Skies over Puttalam

80% of the air pollution load is

contributed by the transport sector

Land Pollution Control

• Integrated Solid Waste Management

• Good agricultural practices

• Remediation of polluted soils

• Prevention of erosion and silting

• Containment of hazardous waste and

waste water treatment using land

treatment techniques

3R Principle

• Reduce

• Reuse

(19)

Compost

Production

Paper

Deaf and Blind School

Abans Env Services / Paper collection

Glass Factory Glass ( 3 types)

Plastics (all types)

Different plastic recyclers

University Colour Code

University Colour Code ––Solid WasteSolid Waste

Blue –waste paper

Orange –Plastics (milk cartons , cups)

Green –Food waste

Noise Pollution Control

• Control noise at source by proper choice

of equipment, design modification,

mounting and proper layout

• Isolation or use of baffles

• Use of ear protection devices

(20)

Desiccated Coconut Industry

DC industry

(21)

Some additional slides for

information

Materials, Energy, Water, Labour, Capital Products, By-Products

Solid Waste Waste Energy, Wastewater Air Emissions

Waste takes many forms

fertilisers (liquid domesticsewage and industrial waste)

minerals esp. nitrates minerals esp. phosphates eutrophication algal bloom competition for light consumers can't consume fast enough

dead plants dead algae

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Harmful Substances

Disinfection byproducts trihelomethanes carcinogenic Agricultural organochlorides persistent Pesticides (DDT) bio accumulate Acids and alkalis inorganic minerals affect biological

life, affect toxicity of CN-_{, S}

-Plastic, lubricant, PCB persistent, lethal rubber, paper even at low level Pharmaceutical, Phenols toxic to fish,MO &

(22)

Physical Effects

Suspended Solids china clay, peroxide, settlement, turbidity metal salts reduce light, photosynthesis organic solids reduce DO

Temperature Cooling water from lower DO, speed up organic power plants matter degradation Oil and grease Refineries, terminals Prevents O2exchange,

storage tanks lethal to birds

Colour pigments, dyes aesthetics, toxic, reduce light penetration

Foaming anionic detergents, aesthetics, carry SS & surfactants pathogens, affects aeration